Centrifugal switch.



H. L. ZABRISKIE.

CENTRIFUGAL SWITCH.

APPLICATION FILED JULY 10. 1913.

1,155,985. Patented 001;. s, 1915.

WITNESSES UNITED s'r TEs PATENT OFFICE.

HENRY L. ZABRISKIE, OF WESTFIELD, NEW JERSEY, LASSIGNOR TO DIEHL MANUFAC- TURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

CENTRIFUGAL SWITCH.

Specification of Letters Patent.

Patented Oct. 5, 1915.

11 b all whom it may concern.

Be it known that I, HENRr L. ZABRISKIE,

a citizen of theUnited States, residing at \Vestfield, in the county of Union and State of" NewJersey, have invented a certain new and useful Improvement in Centrifugal Switches, of which the following is a full,

. clear, and exact description.

This invention relates to centrifugal switches for electrical apparatus, and more particularly to such switches as applied to single phase alternating current or induction motors.

In such motors an auxiliary starting winding is used and it is desirable to cut out this winding when the rotor of the motor approaches synchronous speed, and it is the object of this invention to provide a switch automatically. operated by the centrifugal actionof the rotor for cutting out this windmg.

The invention consists of a number of contact fingers pivotally mounted with relation to the complementary contact surfaces and normally held in circuit making contact with said complementary members by" means of pairs of springs so disposed with relation-- to the fingers as to be sensitively responsive to centrifugal action to break the circuit automatically, as desired, upon theoccurrence of conditions requiring such breaking of the circuit, and equally sensitive to re- .spond to conditions requiring the making of g the circuit again, as I will 35 tion of arrow :27, Fig. 1. Fig. 3 is a section taken on line A B of Fig. 1. Fig. 4 is a view similar to Fig. 1, but showing the contact fingers in their extreme depressed posi-' I tion. 'Fig. 5 is a front view of a suitable contact piece for use with the contact fingers of the switch. a

1 is a "plate of-"sheet metal stamped and shaped in such a way as toform upstanding ears 2 and armsj3. The arms 3 are arranged in pairs,.preferably three, and betweeneach pair is mounted a contact finger 4, having its axis 5 of vibration arranged at the upper n portions of the arms. The contact fingers 4 have formed integral therewith contact tips 6 for cofiiperation with suitable contact plates to make and break the circuit, and stop members 7 which latter are adapted to limit the movement of the fingers by striking against one of the arms 3. The fingers i are so pivoted that the greatest weight is between the pivotal point and the plate 1. These weighted ends of the fingers are pierced at points 8 substantially farthest removed from the axes, and said weighted ends are connected outside of the radius of the axial points with the ears 2 by helical springs 9. Each finger hastwo of these springs attached to it, one on each side and extending therefrom at an angle, and the opposite ends'of these springs are attached to the ears-2. The cars being stationary and the points of attachment of the springs to the fingers being movable in the arc'of a circle aboutthe axial points 5, the points of attachment of the springs to the ears 2 will be centers for the oscillatory movement of the springs. -These ears are of such a -height that a line drawn from the spring its lowermost position, will be almost on a line with the axial point 5 of the fingers 4 at a point opposite such axial point. It will thus be seen! that when the fingers 4 are depressed fully the axes of the springs 9 will rise nearly as hlgh as the axial points of the fingers 4. In this way a very quick and effective spring action is obtained and very little resistance is offered to the centrifugal action of the fingers 4. I I

The plate 1 is-mounted upon a disk 10 of suitable insulating material, which forms a baseby which the switchmay be mounted upon the rotor of the motor.

The complementary part, of the switch is formed preferably of two contact plates 11 (Fig.5) mounted upon the casing ofthe motor and .insulatedtherefrom and from each other by a disk 12 of suitable insulating material. These plates 11 are connected by wires 13 with the motor windings. A

raised portion 14 onthe faces of the plates 11 forms a contact surface against which the tips 6 of the fingers 4 are normally held by the springs 9. It will of course be un-.

derstood that these contact plates are mount- I ed at right angles to the axis of the motor shaft and parallel with the plate 1.

The operation of the switch is as follows: The motor being at rest, the tips 6 of the contact fingers l will be bearing against the raised portion of the contact plates 11 under the .pressure of the springs 9, and as there are threefingers Fl and only two plates 11, it will always be possible for a circuit to be made through the switch. The electric curwhen the rotor has attained a synchronous speed the circuit made by the switch will be broken and the motor will run by the main windings.

It will be noted that as the contact fingers 4 fly out under centrifugal force the lines of action of the springs 9-tend to come toward a dead center, thus giving a very' quick and efl'ectiv'e spring action.

While the invention is designed primarily for use on motors of the characterfirst described, it is not intended to limit it or the scope of the claims to any particular use.- Obviously, therefore, it is within my 'inven-' tion to use the principle of the switch with and without structural alterations wherever it is adaptable.

VVhat'I claim is 1'. A centrifugal switch, comprising a platehaving fulcral arms and ears, contact fingers intermediately pivoted between said.

normally holding said fingers in circuitmaking position.

3. A centrifugal switch, comprising a plate havingfulcral arms and ears, contact fingers pivotally mounted between said arms, and a pair of springs connected to each finger and to said ears on opposite sides of each finger, said ears being stationary and each finger movable in an arc of a circle about its axis, and the points of attachment of the springs to the ears affording centers for oscillatory movement of the springs, so that the tension of said springs remains substantially constant under the movement of the fingers.

4. A centrifugal switch, comprising a plate having fulcral arms and ears stamped up therefrom, contact fingers pivotally mounted between sald arms, complementary contact plates arranged at right angles to the axis of the motor shaft and adapted to be en-- gaged by said contact fingers, and a pair of springs attached to each finger and to said ears on opposite sides of each finger for holding said fingers in engagement with said contact plates.

5. A centrifugal switch. comprising a plate having fulcral arms and ears stamped up therefrom, counter-weighted contact fingers pivotally mounted between said arms, and a pair of springs connected to the counterweighted endof each finger and to said ears on opposite sides of each finger and outside of the radius of revolution of the pivotal points of said fingers.

6. A centrifugal switch, comprising a plate having pairs of arms, contact fingers eccentrically pivoted between said arms and provided with stops to limit their movement in one direction, ears rising from said plate, and springs pivotally mounted in said ears and connected with said contact fingers and adapted to rise and fall with said fingers as they turn upon their pivots.

In testimony whereof I have hereunto set my hand this 7th day of July A. D. 1913.

HENRY L. ZABRISKIE.

Witnesses:

D. Omvnn VVoLcoTr, W. E. CARMICHAEL. 

